Thread-forming mechanism



H. L. BLOOD EAD FQRMING MECHANISM THR Filed may s, 1925 im. 25, 192s.

lilfllli Patented Dee z5, 192s.

UNITED .srATEfsf 1,696,225 PAT-ENT OFFICE.'

.HAB'OLD LANGLY BLOOD, 0I OAK PARK,- IIJLINOIS, ASSIGNOR T0 WESTERNELECTRIC COIPANY, INCORPORATED, F NEW YORK, N. Y., A. CORIQRALIONv OFNEW YORK.

THREAD-nonnina MncHaNrsu.

Application led May 8,

rIhis invention relates to thread forming. mechanisms, and has for itsprimary ob]ect the provision of an improved mechanism for rapidly andeconomically forming threads upon blanks. In order to attainthis objectthereI is provided in accordance with the general features of thisinvention in a machine for forming threads upon screw blanks, means forsuccessively feeding blanks in a predetermined spaced'relationship sothat threads are formed on a plurality of blanks during each Workingstroke of a reciprocating die cooperating with'a fixed die.

Other objects and advanta es of the invention will more fully appearromthe following detailed description taken inconnectionf with theaccompanying drawings which illustrate one embodiment thereof, and inFig. 1 is a fragmentary plan'view of a threadrolling machine embodyingthe features of the invention with the operating I parts shown inposition with two blanks between the threading dies and at the beginningof the threading operation upon the second blank; f

Fig. 2 isa verticalsectional view taken upon the .line 2-2 thereof, and

Fig. 3 is a fragmentary plan view of Fig. 1 showing the relativepositions of the blank feedin Afingers during the positioning of a blanktween the threading dies.

Referring to the drawings wherein like reference numerals designate likeparts through- `Aout the several views, 10 indicates the frame or bedofa thread rolling machine -which may be of any well-known type", allparts not necessary to a complete understanding of the in- L0 v'ventionhaving been omitted. A stationary die 11 is suitably mounted in theframe 10 and a movable die 12 carried on a slide member 13 is arran edto be reciprocated upon a suitable guideway (not shown) provided in the5 frame. A longitudinal reciprocating move- -ment is imparted to theslide 13 through a connecting rod 16 pivotally connected at one end tothe slide as indicated at 17, the opposite end of the rod V16 beingoperatively connected to a crank disk 18 fixed for rotation upon adriving shaft 19 in turn rotated by suitable driving means (not shown)in the direction indicated by the arrow (Fig. 2). Screw blanks 2O arefed from any suitable of the movable die.

1925 Serial No. 28,865.

hopper-mechanism (not shown) down a chute 21, from which they aredelivered one at a time to a position betweenthe stationary and mOvabledies l11' and 12, respectively, by a feedin mechanism to be hereinafterdescribe `Heretofore, in some machines for rolling threads uponscrewblanks a. single blank has been fed to a point between the dies atintervals corresponding to each working stroke of the movable'die,thereby rolling a thread 11pon one screw blank for each: working strokeIn the blank feeding mechanism to fbe presently described in detail twoblanks are fed in succession and properly spaced from each other betweenthe threading dies during the time thel moving die has advanced a shortdistance, so that threads are rolled upon two blanks during each workingstroke of the movable die.

The blank feedin mechanism shown in the drawings will now e described."Associated with the lower end or outlet point of the chute 21 "(Fig. 2)is a mechanically actuated fingerV 22 which retains the descendingcolumn of screw blanks 20 in the chute and at the proper instantseparates the lowermost blank from those.behind it and forces theseparated blanks outwardly and in front of a pusher retracted and readyto begin separating a blank from the column and moving it into positionat the beginning of the next stroke of `the,die 12. The actuating meansfor the fingers 22 and' 23 comprises the following: Secured to the shaft19 for rotation therewith, are cam disks 25 and 26' .provided with camfaces 27 and 28, respectively. The cam faces 27 and 28 are adapted to beangularly adjusted relative to each other, the disk 26 being providedwith a slot 29 of suitable length through which a screw ,30 is insertedand threaded into the disk 25. The head of the screw when clampedagainst the outer disk 26 retains the disks and thereby the cam faces 27and 28 in a set angular relation to each other. The purpose of thisadjustment of the cam faces 27 and 28 will be made apparent hereinafter.

In engagement with the cam faces 27 and 28 is a cam roller 33 rotatablymounted upon a lever 34 fulcrumed at its lower end upon the frame 10 asindicated at 35, the upper end thereof being adjustably secured to a rod36. One end of the rod 36 is threaded and projects through an openingformed in an ofi'- set portion 37 of the lever 34 and at either sidethereof. upon the threaded portion of the rod, is threaded a retainingynut 39. A tension spring 40 suitably connected at opposite ends to'thelever 34`and the frame 10 acts to cause the roller 33 at all times tofollow the cam faces 27 and 28. The purpose of providin for theadjustment of the rod 36 upon the ever 34 will be made apparenthereinafter. The right hand end of the rod 36 is pivotally connected asindicated at 41 to a ever'42 fulcrumed intermediate its ends asindicated at 43 upon the frame 10. To the upper end of the lever 42 ispivotally secured one end of a link 44, the opposite end of the linkbeing provided with an elongated slot 45 within which is adapted toslide a pin 48` fixed in the upper end of a lever 49the lower end ofwhich lever is fulcrulned as indicated at 50 u on the frame 10. Atension spring 51 suita ly connected at opposite ends to the lever 49and the frame 10 normally retains the in 48 at the right hand end oftheslot 45, t e purpose of which will be made apparent hereinafter.Pivotally-connected to the lever 42 in axial alignment with the pivotalpoint of the rod 36 therewith, is a slide 52 upon the opposite end ofwhich is formed the pushing finger 23. Adjacent the slide 52 is anotherslide 53 which is pivotally connected to the lever 49, as indicated atV54, intermediate the ends thereof. The opposite end of the slide 53carries the finger 22 which is secured thereto by screws 55. The slidesl52 and 53 are mounted upon suitable guideways. (not shown) provided inthe frame'10. 1 The operation of this mechanism is as folows:

The shaft 19 revolving in a clockwise direction causes the cam faces 27and v28 of the disks 25 and 26 to en age the cam roller 33 insuccession. The re atlve angular relation of the cam faces 27 and 28which determines the interval of time between the engagement of the camfaces with the cam'roller is first will be formed upon the blank, whilefor the first blank the nuts 39 are adjusted upon the rod 36 to causethe blank'to be inserted between the dies when the threads of the.

dies are properly aligned and at substantially the instant the movabledie 12 starts upon its working stroke.

In Fig. 1 the parts are shown in their relative positions at thecompletion of the feeding movement with two blanks positioned betweenthe threading dies, the moving die having advanced only a shortdistance. As the disk 18 continues to rotate in a clockwise directionthe connecting rod 16 will move the movable die 12 to a point shown indotted outline in Fig.Y 1 whereupon the threaded blanks 20, alsoindicated in dotted outline, will drop free of the dies and into asuitable hopper (not shown). The die 12 thereafter is .returned to theposition shown in Fig. 3 and thereupon the cam face 27 engages the camroller 33 and rocks the lever 34 counter-clockwise, causing the rod' 36and attached finger 23v to move toward the left. thereby turning thelever 42 clockwise an movin the link 44 to the right. As the link 44moves the'spring 51 is allowed. to turn the lever 49 clockwise about itspivot, thereby causing the fin er 22 to advance to the .position shownin ig. 3 to separate a screw blank 20 from the column of blanks in thechute21 and-move it in front of the fin er 23 as shown in Fig. 3. Themovement o the fingers'22 and 23 in opposite directions as justdescribed takes place substantially at the same time and in timedrelation with the movement of the movable-die 12. Immediately upon thefinger 23 feeding a blank in front of the finger 22 and between thedies, the movable die 12 starts to move toward the right upon itsworking stroke and the rolle 33-rides y,down the cam face 27 whereuponthe spring 40 is permitted to move the' rod 36 and atand rightrespectively and positioning an? 'other blarik in front of ,the fin er23. In the continued rotation of the cam 'sks the roller 33 rides downthe cam face 28, thereby movmg the linger 23 toward the right andinserting the second blank 20 between the cooperating dies asl shown inFig. 1 ready foi' the completion of the workin stroke of the die 12. Incase a blank 20 ecomes lod in front of the finger 22 for some reason t eslot 45 permits the various parts to o rate but the finger 22 is notforced towar the right against the lodged blank.

From the foregoing description!J it will be seen that a mechanism isprovided which is of comparatively simple formation in its constructionand the arrangement of its parte and one by which the output of a threadrolling machine of the type described may be materially and economicallyincreased.

`What is claimed is:

l. In a thread rolling mechanism, a pair of die members havingcooperating die faces, means for causing an intermittent relative motiontherebetween to form a screw thread on a blank interposed between saidfaces, and means for successively feeding a plurality of blanks from acommon point to and between.

tween the blanks fed between the die mem bers.

3. In a thread rolling mechanism, a reciprocating slide, a membercarried thereby and having a die face, a fixed member having a die facecooperating with the first mentioned die face for formingl threads on ablank interposedy therebetween, means cooperating in timed relation withsaid slide for feeding a. plurality of blanks between said dies for eachworking stroke of the reciprocating slide and means for controlling thetimed relation of the feeding means and the reciprocating. slide.

4. In a thread rolling'mechanism, a pair of members having cooperatingdie faces, means holding a supply of blanks, a plurality ofoppositely'movable reciprocable fingers for feeding blanks from saidsupply to said dies at predetermined intervals, and means for causing arelative reciprocatory motion between the membersto form a I thread on ablank" interposed between said faces and for causing said fin ers tofeed a plurality of blanks between sai faces during l said threadforming relative movement of the dies. v

5. vIn a thread rolling mechanism, a pair of members having cooperatingdie faces, means for causing a relative reciprocatory motiontherebetween to form a threadl on a blank interposed between said faces,means cooperating in timed relation with said slide for feeding aplurality of blanks between said faces for said thread forming relativemovement of the dies, and means for varying the cooperating timedrela-tion between the first and second mentioned means.

6. In a thread rolling mechanism, a pair ofdles, means for causlng arelative reclpro catory motion therebetween lto form a thread on ablank, means cooperating in timed re lation with said means forsuccessively feeding a plurality of blanks between said dies for saidthread forming relative movement of the dies, and means for adjustingsaid last .mentioned means to vary the time interval between successivefeeding movements thereof.

7. In a thread rolling mechanism, a pair of dies,means for causing arelative motion therebetween to form a thread on a blank, means forfeeding blanks between the dies and a cam member actuated by the firstmentioned means for causing the last mentioned' means to successivelfeed a plurality of blanks during said t read forming relative pmovement of the dies.

8. In a thread rolling mechanism, a pair 'l of dies, means for causing arelative motion therebetween to form a thread on a blank, means forfeeding blanks between the dies, a composite cam member comprising aplurality of cam elements actuated by the first mentioned means forcausing the last mentioned means to successively feed a plurality ofblanks during said thread forming relative movement of the dies, andmeans for-adjusting therelative position of the cam elements to vary theinterval of time between the feeding of the blanks.

.In witness whereof, I hereunto subscribe my, name this 30th day ofApril, A. D., 1925.

HAROLD LANGLEY BLOOD.

